Clutch



Jan. 3, 1950 1., E. LA BRIE 2,493,721

CLUTCH Original Filed Feb. 20, 1941 4 Shee ts-Sheet 1 INVENTOR I E ud ar 2. 142577:

ATTORNEY Jan. 3, 1950 L. E. LA BRIE CLUTCH 4 Sheets-Sheet 3 Original Filed Feb. 20, 1941 rllll A h K M. Y llr Jan. 3, 1950 L. E. LA BRIE 2,493,721

CLUTCH Original Filed Feb. 20, 1941 4 Sheets-Sheet 4 INVENTOR ill/ e r 2. 14,2? 6.

WWUQLM ATTORNEY- Patented Jan. 3, 1950 Ludgcr E. La, Brie-,- Detroit, Mich., assignor to Chrysler Corporation, Highland Park, Mich, a;

corporation of Delaware Original application February 20, 1941!; Serial No. 319,786, new Patent No. 2,374,688, dated May 1,

1945, Serial No. 59054253 This. invention relates to clutches in. general and in particular to clutches of the. servo type, and is a division of my copen-ding application Serial No. 379,786,. filed February 20, 1941, new Patent No. 2,374,688}. dated May 1, 1945..

The principal. object oi my invention is to provide a servo clutchwhich. is more compact, easier to operate and. smoother in operation than those of'thepri'or art.

An additional, object is. to. provide a. clutch. of. th'm type which is readily adapted for manual or power operation.

A further object is to provide simple. and. effective means for initiating operation of the servo:

mechanism for controlling engagement of. the. clutch.

A still further object is to provide. novel and efficient power actuating. mechanism. for clutches of this general type.

A still further object is to provide an. expandiing spring type clutch wherein torque may be transmitted in either directiomtliusmaking. possible use of clutches of this type in installations where overrunning or free-wheeling. of one shaft or structure relative to the other is not. de-

sired.

Further objects and advantageswill' become apparentfrom. the following descriptionof' preferred. embodiments of the. invention, reference being made to the accompanying drawings in which:

Fig. 1 is a longitudinal elevational View, partly in section, of an embodiment of. the clutch adapt.- ed' for manual operation;

Fig; 2 is a view of the clutch expansion spring. and actuating lug as viewed along theline 22 of. Fig: 1;

Fig. 3 is a fragmentary view of the-parts. shown in Fig. 2.- as seen when looking. in. the direction of. the arrow 3';

Fig; 4 is a sectional view taken along line 4-4. of Fig. 1;

Fig; 5 isv a fragmentary sectional viewalong. line 5-5 of' Fig. '1;

Fig. 6is a fragmentary view of the Fig. 1 clutch adapted for differential fluid pressure operation;

Figs; 7, 8, and 9 are similar views ShOWing. the clutch adapted for operation respectively by mag netic means, by a solenoid and by electrical eddy current means;

Fig. 10' is a fragmentary sectional view along the-line I'll-Ill of Fig; 9;

Fig. 1 1 is a longitudinal elevational view, partly in section, of a further modification; and

Fig. 12' is a sectional view along, line 1'2-4'2 of Fig; 11.

Divided; and. this applieattien April 26,

10 Claims. (01. 172- 34) Referring now to Figs/1.45;. inclusive my improved-clutch. is illustrated in a typical envirom merit torming. a. releaseable th iving connection. between. a driving shaft in and a driven shatt I. I1.

The former is preferably adapted to be driven by: a prime mover and the latter connected. towa load suchas for example, theinpu-tshaitof a motor vehicle. transmission. Itis, however, obvious that my improved clutchis not necessarily restricted in use to thespecific relationship shown v I Splined. on. the driving. shaft. M1 at. i2 is the clutch. d-riving'elenrent $3 which for. convenience of. mam;taeture is made: up of. two. parts it and.

i5. riveted-v together at it, A retaining nut. it threadedly engages the hollowed-out. end portion. of the shaft H1 at 1.8 and serves to retainthe. clutch element. It against displacement. Thedrivenshait It is. reduced in size at oneendz and is pilotecl in. the hollow end. of shaft til, an. antifriction bearing rotatably separating. the two..

The driven element of the clutch comprises the. structure. 23, whichior convenience: ofi manufactureis made up of the.- parts- 2!. and 2.2 riveted: together at. 23'. Therelemerat 261s splined on theshaft M at. 2A. The portion 22. thereof carriesthe clutch engaging. element which. consists oi} a. coil. spring 2 5* staked: at one end. thereot 25 (Fig.2);to the driven portion 2 2 by pins. 26 and,

27.. spring. 25 is. formed. of. spring material;

of. substantially rectangular cross-section; and is wound. suchthatit is adapted to normally closely engage. the outer. cylindricalsurface 28 of. the.

portion. 22. of. the. driven. element 2!}. The opposite end 25 (Fig. 2.).- of the. spring, is. adapted for. engagement by a lug 29. which. is riveted at 30 to theclutchpilotmember 3i, A pin (Fig.

2). retains. the spring: 25-endwise. on: the portion.

has a conically shaped. inner. surface, is adapted to telescope the. rearwardly extending portion of. the; driving element i3 asillnstrated. in: Fig. 1..

The latter is formed with a. conical clutch. surface 34 with which the triction material. 33 is. adapted. toengage.

Te. member 3| is urged by. a coil. spring; 35 into such position that the frictionmaterial 33 engages the clutch surface 34 and under such circumstances, clockwise rotation of shaft ID will cause corresponding rotation of pilot member 3|. This will, in turn, cause the lug 29 to exert pressure on the rear end 25 of spring 25 tending to unwind the spring. Unwinding of thespring 25 will be accompanied by increase in diameter thereof and the outer surface of the spring will engage the inner cylindrical surface 36 of the driv ing element portion thereby establishing a torque transmitting connection between the ele-' ments l3 and 20.

The spring 35 reacts against one race of an antifriction ball bearing 36, preferably of the sealed type, which is prevented from displacement along shaft I I by snap ring 31.

It is of course apparent that, as so far described, the clutch will transmit torque in one direction only. This is necessarily true because, if the driving thrust is shifted from shaft II] to shaft l (as would occur upon coasting of the vehicle in a motor vehicle installation) the spring will tend to wind up under inherent tension, there no longer being thrust imposed thereon by lug 29, and thus will disengage from the surface 36'.

In order to prevent overrunning of the shaft relatively to the shaft l9 and to provide twoway torque transmission through the clutch, a reverse type roller clutch device is operativel disposed between the elements I3 and 20. This roller clutch device comprises a set of overrunning rollers 3B which are retained in spaced relation by a cage 39, a spring 40 being provided for urging the cage toward driving position as is conventional in these types of clutch devices. The outer surface of the member 2| is provided with a set of cams 4| in the vicinity of the rollers and these cams are so shaped that the rollers will wedge between the higher portions of the cams and the inner cylindrical surface of the member I4 whenever the member 2| tends to rotate faster than the member M.

The pilot member 3| may be disengaged from the driving member I3 by a release mechanism which includes an anti-friction release bearing 42. The inner race 43 thereof is staked to the :pilot member 3| by snap rings 45 and the outer race of the bearing has a driven fit with the inner cylindrical surface of a release collar 46. latter has a shoulder 49 adapted for engagement by the depending ends 41 of a release yoke 48 which is keyed at 50 to a shaft 5|. The shaft 5| is adapted to be operated by any suitably constructed manually actuated mechanism such as a pedal or a hand operated linkage.

The operation of the clutch will be readily understood from the above description, it being apparent that the spring 35 will act to engage the friction shoe 33 with the conical surface 34 of the driving structure, whereupon the pilot member 3| will rotate in the direction of the driving structure and the lug 29 will unwind the clutch spring 25 carried by the driven structure which will frictionally engage the surface 35 of the driving structure and thereby establish a driving con nection between the two structures. Rotation of the shaft 5| in a counterclockwise direction will disengage the friction shoe and conical surface thus permitting release of the said driving connection because the spring 25 will immediately contract due to its inherent tension in response to a release of pressure at the lug 29.

Tendency of the driven structure to overrun the driving structure will also permit the spring 25 to The,

- between the shoe 33 and the surface 34.

contract and under these conditions the drive will be transmitted through the rollers 39 which will wedge between the members l4 and 2|. By properl adjusting the clearance between the rollers 39 and the cams 4| with relation to the slight r0- tation required to fully engage the spring 25 with the member i5, it is possible to reduce the backlash upon torque reversal to an extremely small amount which is practically unnoticeable.

through the friction connection established by the spring 25 than through the friction connection y other mechanical advantage derived may of course be obtained by varying the sizes and adjustment of the parts.

My improved clutch is particularly well adapted for power control and I have illustrated several different applications thereof.

Fig. 6 illustrates the clutch of Fig. 1 adapted for fluid pressure control. The pilot member 3| in this form of the invention is formed with an overhanging annular portion 52 which forms a fluid pressure cylinder adapted for reciprocation along the shaft against the spring 35 a bearing 36 accommodating relative rotation between the pilot member and the spring. A stationary piston 53 surrounds the shaft II and has a chamber 54 which communicates with a source of pressure fluid through a pipe 55. The chamber 54 is connected by a passage 56 with the chamber 51 of the cylinder 52. A snap ring 58 prevents rearward axial movement of the piston 53 and suitable rings 59, 69 and'Bl are provided to insure a fluidtight assembly. By providing a suitable valve for controlling admission of pressure fluid to chamber 54 the engagement of the pilot member 3|'-' with the clutch driving element |3 may be controlled.

Fig. 7 illustrates the Fig. l clutch adapted for magnetic control. In this modification the portion W of the clutch driving element i3 is formed with a rear annular portion 62 which carries a field coil the latter being connected by a wire 54 with a collector ring 65. The ring 65 is carried by an insulating ring 58 carried by the member i5 Acarbon brush 55, carried by an insulating plug 9%, is connected by means of a wire 69 with a source of electrical potential, the return being effected through the metal of the assembly, which is intended to be grounded in accordance with conventional motor vehicle practice.

The brush 63 is mounted on a stationary part for receiving the insulating fitting 61 and a spring l2 which is adapted to urge the brush 55 into contact with the collector ring 65. The clearance between members and (N is slight (in the order of eight to ten thcusandths) and a friction ring '53 of asbestos fibre or other suitable clutch facing material is carried by the annular portion 52 as shown.

Upon energization of the field coil 63, the pilot member 3| will be attracted by the magnetic flux flowing around the magnetic circuit surrounding the coil and will move axially against the force of the spring 35 into contact with the member iii A snap ring 14 limits the movement of the pilot 3| under the force of the QsQQQ ZQL trin e -ta t e imit of. the desired learanc n. he. orm of t e ve on ll s atedin ma an elec ri l. ole d. n ra y d i na e atld. controls the action of the pilot member 3&9. The, solenoid includes a field coil 16. carriedby an iron field s ructure it whichis mounted on a stationary part '58 of the assembly. The pilot 31 has a rearw rdly extending sleeve portion '19 which is reduced tcv receive an annular iron core, 8d, the latter being held against displacement e l/ .10.6. aiqresaid reduced portion, by a ring 8|.

The coil 16 is grounded to the metal structure at one, end and the other end is adapted, to beconnectedby a wire 82 with a source of electrical energy, a suitable contact structure 83 being; proyided. inasmuch as the coil is. stationary, no ush. or slip. r g s n s ary;

'Thepilot 3,5 is normally urged axially against the ring ti t, by the spring and upon energizetion" of th solenoid field. coil 16, moves axially toward the left of Fig. 8, to engage the friction oe. 3. o t s -t clu ch.

Inthis-modification, the: pilot M and the ring 78" wl; 1 i separates the field structure from the part iii are preferably made of stainless steel which is of; extremely high reluctance, thereby cqlifihi lg the flux path to the iron of the solenoid. Figs; 9 and 1.9 illustrate the Fig. l clutch adapted; for eddy-current control. In this form of ne deyiee, the stationary part of the assembly, 8-? carries annular iron field structure 85,. Thelatter is li -shaped in cross section and carries a field coil hi adapted for energization, through a; wire it connected to one end. thereof, the other end of the coil being grounded. A stainless steel separator ring 88 is interposed be,- tween the fieldstructure B151 and the portion 84 andjf or best results the driving member l5, and. the pilot St are also preferably made. of, non -magnetio material.

iron ring is riveted, at. 9B to the member and constitutes the driving, element, of, the eddy-current pilot clutch structure. The ring 89 provided with a plurality of circumeferen.-. tial'ly equally spa ed teeth, 9i around, its inner surface The teeth til. are adapted to. align radially with a similar set of teeth 92 formed on the. outer periphery of an iron ring 93, carried by the pilot member Bi as illustrated. The. pilot member an integral lug 29? for actuating the spring 25' and is fixed against axial displacement.

on the driven shaft 5 l by washer 9d and. snap Energization of field coil iihwill, cause magnetic,

flux. toff lo through the field structure 85 and air gap between the bifurcated portions,

through regions of high and low flux density, thus the flowing through said point varies in magnitude and eddy currents are induced in the members 8i-and 3; These eddy currents flow in'a direction perpendicular to the path. of the flux-and range in voltage in accordance with the.

speed: o f the driving member 89. 'fjheyjinducea fluxof their own which reacts with the "main flux and tends to prevent relative rotation 'betweenf the members as and '33; This is in, accordance,

with l ww ieb. sta es. n effect. that hang ma nitude r magnetic fie d induces.

ac rent s dir cted ha ts aenetic effect tends to. oppose the magnetic change which produced it.

The effectof he fluxflowing, through the teeth 9 and 9% then, will be tooppose relative rotation between. members; 89 and; 93, and. as. 859 is. rotated at the speed of the driving shaft it, the member-d3 together with the pilot 3M will be rotated. long as there is slippage. between.

membe -S. 8,9- and 93; there will exist an eddy-current-produced torque tending to accelerate the; member 93; to the speed of member 89. Whenv the; two, members; are rotating in synchronism,. a.

;; iven point on ither: of members 89; and 93; wilt be; subjected to flux of constant magnitude and no eddy currents will be induced. Under this. condition the holding force tending to keep the members aea dv .93 in synchronism will be entirelymagnetic. It, is, however, apparent, that. any tendency for the member 93 to slip Will instantly opposed by the eddy-curr nt-produced torque. 1

In practice it. willbe found that the spring 25 grips the member I5 very quickly after coil; 8.6: is, energized and. the magnetic effect of the flowing through the teeth 9t, 92 is sufficient to provide the-force necessary to. keepthe spring ex: panded.

It is believed to-be apparent that the clutches illustrated in Figs. 6 to; 10, inclusiye operate similarly, to the clutch of Fig. 1, it being intended in- 1 all of. the various forms of the inventionto, pro

vide a ratio of approximately fifty to one between the torque transmittedbythe pilot clutch Struc-r ture and thattransmitted through the clutch as a whole.

Any of the-various modifications are adapted fol. mltomatic as well as manual operationas will.

be apparent to: those skilled in the art.

Figs, 11 and l 2' illustrate a modified form of. they-invention wherein; reverse torque is transmitted through the pilot clutchestructure. thisformof; the invention, theoyerrunning rollersfsse are of smaller size than those-used in the aboyedeScribed-formsand are disposed between; the driy'en. shaft It onwhich thecams die. are. fortified and the spring energizing lug 23 the latter having an integral ring portion 95 adapted to-beengagedby the rollers 38 The roller cage th has a his which engages a.

groove the shaft H at 98 for maintaining the rollers against axial displacement. In operation, the. Spring 25. is energized by the lug 29 which is. driyen, throughithe pilot 3i during clockwise rotation. Qf the'shaft l0, When shaft 80 tends to overrun. shaft [l the lug 299 is rotated through thefriction. shoe 3.3; and when shaft l-l tends to overrun shaftflllf, the lug 29 and pilot member 3!v arerotated through rollers 33 thus reversetorque is transmitted from shaft I! to shaft I0 throughthefriction shoe 33,. It is of course apparent, that. only a small fraction of the torque capacity of, the clutchcan be handled by the pilot structure. However, in some installations, such as in. light vehicles, the torque transmission during coasting is relatively. light and is readily handled by the, pilotmembers.

Among other advantages, this form of clutch permits complete disengagement of the drive be,

tween the two shafts. When the shaft 5! is oscillated. to move the release member 46 axially of shaft H. against spring 35, the friction shoe 33- is disengaged from the conical surface of the driving:-

. structure,. the, lug 29 is disengaged from: driving;

engagement with the spring 25, and the rollers 38' cannot establish a drive between the shafts. Thus the driving connection between shaft l and II is completely broken. In the previously described forms, the overrunning rollers are disposed directly between driving and driven members of the clutch, therefore the normally driven shaft II can never overrun the normally driving shaft l0 even when the energizing lug is in non-energizing condition. a

It is of course obvious that the construction of the Fig. 11 clutch may be readily applied to the power actuated clutches of Figs. 6-9, inclusive, to provide two-way torque transmission and to permit complete release of drive between the two shafts; consequently a detailed description is I believed unnecessary.

I claim:

1 In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means; each of said rings having an annular magnetizable portion, a field structure including magnetizable portions straddling said magnetizable portions of said rings and providing a magnetic circuit for said magnetizable ring portions; a field winding for energizing said magnetizable portions; and a plurality of polar projections on one of said rings in its said magnetizable portions arranged in juxtaposition with the said magnetizable portion of the other ring.

2. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between'said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means; each of said rings having an annular iron portion; a field structure including iron portions straddling said magnetizable portions of said rings and providing a magnetic circuit for said iron portions of said rings; a field winding for magnetically energizing said iron portions of said field structure and rings; and a plurality of polar projections on one of said. iron portions of said rings arranged in juxtaposition to the iron portion of the other ring.

3. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means, each of said rings having a cylindrical iron portion and said portions being arranged in radial juxtaposition; a field structure including iron portions in radial juxtaposition to the said iron portions of said rings providing a magnetic circuit for said iron portions of said rings; a field winding for magnetically energizing said iron portions of said field structure and rings; and a plurality of polar projections on one of said cylindrical iron portions arranged circumferentially in juxtaposition to the iron portion of the other ring.

4. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means, each of said rings having a cylindrical iron portion and said portions being arranged in radial juxtaposition; a field structure including iron portions straddling said iron portions of said rings and providing a magnetic circuit for said iron portions of said rings; a field winding for magnetically energizing said iron portions of said field structure and rings; and a plurality of teeth on one of said cylindrical iron portions arranged circumferentially in juxtaposition to the iron portion of the other ring.

5. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring internally of said first mentioned ring and operatively associated with said drive establishing means, each of said rings including substantially concentric cylindrical iron portions having inner and outer cylindrical surfaces, the iron portion of said first mentioned ring connecting a non-magnetizable portion thereof; a stationary field structure including iron portions providing a magnetic circuit for said concentric iron portions of said rings; a field winding for magnetically energizing said iron portions of said field structure and rings; and a plurality of polar projections on the inner cylindrical surface of the outer of said iron portions and a plurality of polar projections on the outer surface of the inner of said iron portions.

6. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means; each of said rings having a cylindrical iron portion including an inner and an outer surface; a stationary field structure including annular iron portions straddling the iron portions of said rings; a field winding for energizing said iron portions; all of said iron portions being spaced apart radially of each other and the said iron portions of said rings each having a circumferential series of polar projections arranged thereon, one series being on the innercylindric surface of one iron portion and that on the other being on its outer cylindric surface.

7. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means, each of said rings having an annular magnetizable portion connecting a non-magnetizable portion thereof and said magnetizable portions being so constructed and arranged as to have a surface on each closely spaced from and in juxtaposition with the other; a stationary field structure including magnetizable portions providing a magnetic circuit for said annular magnetizable portions of said rings; a stationary field winding for energizing said magnetizable portions; and a plurality of polar projections on each of said justaposed surfaces of said annular portions for inducing eddy currents in its juxtaposed annular portion upon relative rotation between said rings to thereby cause actuation of said drive establishing means to establish drive between said driving and driven members, said polar projections being adapted for relative alignment upon establishment of said drive for magnetically retaining said drive establishing means in its actuated position.

8. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means; each of said rings having an annular magnetizable portion connecting a non-magnetizable portion thereof and said magnetizable portions being so constructed and arranged as to have a surface on each closely spaced from and in juxtaposition with the other; a stationary field structure including magnetizable portions providing a magnetic circuit for said annular magnetizable portions of said rings; a support for said field structure; a member of high magnetic reluctance between said field structure and support; a stationary field winding for energizing said magnetizable portions; and a plurality of polar projections on each of said juxtaposed surfaces of said annular portions for inducing eddy currents in its juxtaposed annular portion upon relative rotation between said rings to thereby cause actuation of said drive establishing means to establish drive between said driving and driven members, said polar projections being adapted for relative alignment upon establishment of said drive for magnetically retaining said drive establishing means in its actuated position.

9. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring drivingly connected to one of said members; a second rotatable ring operatively associated with said drive establishing means; each of said rings having an annular iron portion, said iron portions being so constructed and arranged as to have a surface on each closely spaced from and in juxtaposition with the other; an annular shaped field structure of U cross-section having iron leg portions coaxial with said iron portions of said rings and straddling the same; a stationary field winding within said field structure for energizing said iron portions, of said field structure and rings; and a plurality of polar projections on each of said juxtaposed surfaces of said annular portions for inducing eddy currents in its juxtaposed annular portion upon relative rotation between said rings to thereby cause actuation of said drive establishing means to establish drive between said driving and driven members, said polar projections being adapted for relative alignment upon establishment of said drive for magnetically retaining said drive establishing means in its actuated position.

10. In a servo clutch mechanism having a driving member, a driven member, and means for establishing drive between said members, an eddy current structure for actuating said drive establishing means; comprising a rotatable ring including a portion of high magnetic reluctance drivingly connected to said driving member and supporting an annular iron portion of high magnetic permeability; a second rotatable ring including a portion of high magnetic reluctance 0-peratively associated with said drive establishing means and supporting an annular iron portion of high magnetic permeability, coaxial with and in radial juxtaposition with said first mentioned annular iron portion; a stationary field structure having annular iron portions between which said annular iron portions of said rings may rotate, a field winding for energizing said field structure and rotatable iron portions and a circumferential series of polar projections on each of said rotatable annular iron portions and in juxtaposition to each other, the said polar projections of each series being adapted for radial alignment.

LUDGER E. LA BRIE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 700,839 Sessions May 2'7, 1902 1,303,503 Schnuck May 13, 1919 FOREIGN PATENTS Number Country Date 348,434 Germany Jan. 4, 1921 352,614 Germany Apr. 28, 1922 

